Cord connection and strain relief



Dec. 16, 1952 s, L PEDERSEN 2,622,121

CORD CONNECTION AND STRAIN RELIEF Filed Mar-:Ach 2, 1948l 5 Sheets-Sheet l Dec. 16, 1952 Q L PEDERSEN 2,622,121

I CORD CONNECTION AND STRAIN RELIEF' Filed March 2. 1948 5 Sheets-Sheet 2 Dec. 16, 1952 5- PEDERSEN 2,522,121

CORD CONNECTION AND STRAIN RELIEF Filed March 2 1948 5 Sl'xeebS--Slleel 5 Patented Dec. 16, 1952 rence T CORD CONNECTION AND STRAIN RELIEF Svend Laesse Pedersen, Copenhagen, Denmark Application March 2, 1948, Serial No. 12,658 In Denmark March 7, 1947 1 claim. 1

The present invention relates to the connection of electric cables with electric accessories such as plugs, lamp-holders, wall sockets and any other kind of electric accessories. y

It is the main object of the invention to provide an assembly for such uses in which the cables can be connected in a very easy manner and very rapidly and at the same time provide an exceedingly safe connection including a safe holding of the wire at the input end.

Further objects and advantages of the invention will appear from the following specicaton.

The invention will be explained in detail in connection with the drawing in which Fig. 1 shows the one half part of an accessory according to the invention, with the clamping member removed,

Fig. 2 vshows the other half part of the accessory,

Fig. 3 shows the clamping member used by the embodiment shown in Fig. 1,

Fig. 4 is a section along the line IV-IV in Fig. 1,

Fig. 5 is a section along the line V-V in Fig. 1,

Fig. 6 shows a complete accessory in form of a plug provided with a detail shown in Figs. 1-5,

Fig. '7 shows a corresponding accessory in the form of a lampholder,

. Fig. 8 shows one half of another embodiment with the clamping member in the input position for the wires,

Fig. 9 shows the other half from the inside,

Fig. 10 is a side View of the clamping member, partly in section after the line III-III in Fig. 11,

Fig. 11 is a section along the line IV-IV in Fig. 8,

Fig. 12 is a perspective view of a further embodiment of the invention,

Fig'. 13 is a perspective view of still another embodiment, and

Fig. 14 is a perspective detail view of the insulating plate shown in Figs. 1, 4, 6 and 7.

In Fig. 1 is shown one half part IU and in Fig. 2 another half part I2. The half part I0 of the housing in Fig. 1 has an input-opening I4 for the ends of a pair of electric wires and by means of a wedged-formed wall I6, the opening is separated in two canals I8 and 2B. The wall I6 only extends a very short distance into the housof the housing I0. By means of a depressed insulating plate 2S, see also Fig. 4, a ceiling is formed in the canals I8 and 20. At the bottom of these canals are provided metallic strips 28 and 3S which are electrically connected with the poles of the accessory not shown inFig. 1. The platel has cut away parts so that the metallic strips 23 and 3G in Fig. 1 are accessible from above.

The other half part I2 of the housing is provided with a recess extending over the whole area occupied by the canals I8 and 2l] and the middle wall 24 in Fig. 1, but not extending in direction of the input-opening, at which the part I2 is closed.

Between the two parts IIJ and I2 of the housing, which are assembled, as shown, the clamping member 32 shown in Fig. 3 is arranged. This clamping member is formed as a plate and has three legs 34, 36, 38 of which the legs 34 and 36 are adapted to extend down in the canals I8 and 23 at the poles, Where the metallic strips 28 and 3l] are arranged and the leg 38 is adapted to extend down in the canals between the plate 26 and the wall I6.

The two half parts are, as shown in Fig. 4, assembled by means of a screw 4t, which can rotate freely in openings 42 and 44 in the two half parts of the housing, but which is connected with the clamping member 32 by internal screw-threads in a hole 4S therein. At one end the screw 4G is provided with a head 48. and at the other end it is rivetted, so that the two half parts of the housing cannot be separated.

From the above specification, see also Fig. 4, it will be understood, that by rotating the screw 40 at the head 48 the clamping member 32 will be moved in direction towards and away from the metallic strips 28 and 30 and thereby locking or releasing a pair of wires, the uninsulated ends of which are put in through the canals I8 and 20 and simultaneously the leg 38 of the clamping member will loch the wires in the neighborhood of the input-opening and thereby relieves from pull actions.

In Fig. 8 the half part of the accessory, which also within the scope of the invention can be a plug, a lampholder or any other accessory, is denoted by I5 and in Fig. 9 the other half part is shown at I2.

' The part IG has an input-opening I4 which by means of a wedged-formed intermediate wall a short distance from the opening is separated in two canals I8 and 2G, the bottoms and sides of which are formed by the outer walls of the strips 28 and 38 are arranged. said metallicl strips being electrically connected with the poles not shown.

The recess 68 is extending transversely over the accessory to the outer walls of the canals and at both ends of the recess there are. smaller recesses 62 and 64, also of half-cylindrical form and with smaller diameter than the recess 60. Correspondingly the other half part I2 of the housing is provided with a recess B6 which at its ends isv provided with other recesses 88 and 'I0 of smaller diameter.

The inside of the half part I8 of the accessory is Dlane, but the half part I2 is provided with a longitudinal recess '12, 14, separating the part I2 in two half parts which are connected by a narrow part 'I6 which is also thinner than the remaining part of I2, see Fig. 1l.

When the two half parts of the accessory are assembled the'cylinder-formed recesses 88, 66 and theend-recesses 62, 68 and 64, 'I0 will form bearings for a clamping member 88 provided with a cylinder-formed part which at the ends has pins 82, 84 with smaller vdiameter than the clamping member, which substantially corresponds to the diameter of the cylinder 60 68. The pins will correspond to the smaller cavities in the housing.

Furthermore the clamping member is provided Witha plate-formed part 86, see Figs. 10 and 11,

andirr the cylindrical part are provided holes 88 and 98 o-f such a diameter and so arranged that theyr form extensions of the canals I8 and 28, see Figs. 8 and l1. The plate-formed part 88 is arranged substantially at a right angle to a plane through the holes 88 and 98seeFig. 11.

It will be understood from Fig. 11, that the wires 82` the uninsulated ends 94 of which are put in through the canals I8 and 28 and in the holes, 88 and 90 will be clamped and simultaneously brought into electric connection with the metallic strips 28, byV turning the clamping member-80, 86 in direction of the arrow shown in Fig. 11. To prevent breaking or other damaging of the uninsulated wireends one side of the holes can at 91, as indicated in. Fig. 11, be rounded and the metallic strips can be resilient;

From Fig. 11 it will further be understood that the plate-formed part 86 of the clamped member in closed position will be cover for the remaining part of the unit, because it lls the recess 12, 'I4 in the part I2. The underside of the part 86 has a recess 96 to make space for the bridge 'I6 which connects the two side parts of the part I2. Furthermore the clamping member at the upper side of the plate-formed part has a projecting part 98, which in closed position co-operates with the end of ther wires in the opening |4 in order to secure the wires here.

The two parts l!) and I2 of the unit are held together by means of rivets o1 screws arranged in holes |88 and |02, and the plate-formed part of the clamping member is in the clamping position secured by means of a screw which is inserted through a hole |04 and a screw-threaded hole |86 in the part I 0.

The embodiment shown in Fig. 12 only differs from that shown in Figs. 8-11 thereby that the clamping member 86 is forming the whole part of the accessory and is not borne between two parts connected with each other. The half part I0 has, as in the other embodiments an outwardly extending edge, but this is higher than the intermediate wall 24. In Fig. 12. the. clamping member 86 is borne by means of' a Ashaft III) inserted through holes I I I in the part IIJ and there is provided a cam denoted by which is separated in two parts 80a and 88h.

Furthermore transverse walls ||2 and I I4 are arranged in front of the parts 80a and 80h in the canals I8 and' 20 and in this case it is not necessary to. provideholes in the cylindrical parts 80a and 88D. The transverse walls |I2 and |I4 will further act to clamp and hold the ends of the wires which when the clamping member 86 is swung downwardly will be bent just in front of the clamping point and therebybe safely locked. In Fig. 12 there is shown a screw Il iil for holding the two parts together. y l

The arrangement described above can be used in connection with practically all kinds of electric accessories, for instance as shown in Fig, 6 in connection with the plug, the legsY 58 and 52' of which at their rear ends are directly connected with the metallic strips 28 and 38 or, as shown in Fig. 7, in electric lampholders, in which a screw-threadV 54 and a bottom screw 56' respectively are connected with each of the metallic strips.

The parts I|2 and I'I4 on each side of the insulating central piece 24 in Fig. 12! are preferably formed of conductive material. These maybe continuations of the strips 28 and 38 or may be spaced slightly therefrom. In either case, it is desirable to form the surfaces of the parts 88d. and 80h of conductive material' as shown in Fig. 13. In the instanceswhere the parts II2and. I I4 are conductive, but spaced from the strips 28 and 30, the conductive surface on the parts 88a, and 80h will bridge the spaces and form" portions of the conductive pathsl along the leads 28-50 and 30-52. In the case shown in Fig. 13 where the portions II2c and ||4c are continuations of the stri-ps 28 and 3U, the metallic surfaces I:I1 andi I 8 act to insure the effective provision of a conductive path. l

In Fig. 13, also, there are illustrated serrations |I9 and |20 to firmly clamp the electrical cord, the Wire ends of which are clamped by the cam surfaces against the lead-portions |`|2c andA I I4c.

It will Ibe understood that even when the drawing only shows a plug and a lampholder as samples the application of the4 inventionV is not limited thereto and that the invention can be' applied. by practically all sorts of electric accessories such as wall-sockets etc.

I claim:

A cable connection and strain relief compris# ingV an insulating housing having on the interior a surface for supporting saidcable, interior poles within said housing for the connection with the cable Wires, said housing having .adjacent said surface an input aperture for said cable. an insulating clamping member hinged to said housing about a pivot and forming4 a cover for said surface in saidhousing and being. movable about the pivot axis to and from an active covering position, said surface extending substantially parallel to said axis, cam-surfaces associated with said clamping member opposite. the poles, said poles terminating in faces disposedlongitudinally of said pivot axis, and said cam-sur- UNITED STATES PATENTS faces being with said member movable about Number Name Date said axis, to press the wires of said cable 1 383 764 Sargent July 5 1921 into Contact engagement with said faces of said 2112752 Abbott S11/1m. 29 1939 poles, and a projecting part formed on said 5 2121963 Walter Jun'e 21 1938 clamping member and protruding from the outer- 2129811 Bissen Sept 13' 1939 most portion thereof opposite relative to said axis 2159964 Wamel. May 23 1939 and disposed adjacent said surface to clamp 229-3177 Bramard May 19 1942 therewith said cable, and being movable about 2399996 Benander Apr' 23' 1946 said axis at right angle to said surface for cable 10 2:409045 001.111.611 Sem-1 24 1946 feease- 24351341 crumrine Feb. 3,J 1948 SVEND LESSE PEDERSEN' 2,466,930 cook Apr. 12, 1949 REFERENCES CITED FOREIGN PATENTS The following references are of record in the l5 Number Country Date 111e of this patent: 622,051 England Apr. 26, 1949 

